Certain ground vehicles, such as those utilized in military and similar applications, use hybrid electric technology including high voltage DC power generation. A typical electric power system architecture includes an un-regulated permanent magnet generator coupled to a boost type pulse width modulated power converter, such as an active rectifier, and a high voltage battery.
Multilevel topologies for achieving this system have been considered in order to achieve a low harmonic distortion with moderate switching frequency and reduced electromagnetic interference emissions compared to standard two-level active rectifiers/inverters. In some applications, the near constant power load over the duration of vehicle operating time from a base load can be coupled with high peak loads that occur periodically, or for brief durations during the operation of the vehicle. To support the peak load requirements, re-chargeable high energy storage batteries are included within the electric power system. Such systems, however, may require additional power dissipating resistors handling regenerative loads with fully charged batteries.